Ellie Camarena and Whitley Bilges were chillin' in the cafeteria at the University of Memphis' University Center.

That's when it happened.

They and millions of other cell phone users — an estimated 225 million nationwide — heard an I-will-not-be-ignored alert tone on their phones.

No gentle dinging or pinging, no chirping or chiming. Just a chorus of loud, Amber alert-type high-pitched tones at precisely 1:18 CDT Wednesday afternoon. There was no getting away from it; the president wanted to talk to us all.

OK, so it wasn't actually the president — at least not this time — even though the message said "Presidential Alert." It was a shared national moment as the Federal Emergency Management Agency tested its new Wireless Emergency Alerts (WEA) system, similar to the frequent tests of the Emergency Alert System (EAS) on television and radio. Those platforms, in fact, began broadcasting similar messages at 1:20 p.m., just after the phone texts.

Confused looks filled the building as everyone glanced at phones on tables, fished them out of back pockets or scrambled to retrieve them from backpacks. Many clicked out of the message after a quick glance and walked on expressionless, while others exchanged "what was that?" looks with others.

"I don't like it," Bilges said. "I think it's kind of invasive."

Camarena said she understands why officials want to do it, but she still thinks it's "kind of strange."

At a table nearby, Katherine Lothrop said she had heard the test was going to occur, but she wasn't sure when.

"I don't think it's a good idea," she said. "You can't turn it off. What if I'm in class?"

Ordot/Chalan Pago Mayor Jessy Gogue, left, talks to FEMA officials during their post-typhoon assessments in his village Thursday morning. Typhoon Mangkhut passed through the Marianas Sept. 10, and Gov. Eddie Calvo said he intends to request a federal disaster declaration in order to obtain assistance for the recovery. Courtesy of Jenna Blas, Guam Homeland Security/Office of Civil Defense

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After a moment's thought, she added: "If it's that important, then I guess they need it. But I hope there are enough checks and balances in place."

FEMA said in a release that the test was intended to ensure both WEA and EAS were effective ways to communicate with the public in emergency situations, especially national emergencies.

"Testing of public alert and warning systems helps to assess the operational readiness of alerting infrastructure and to identify any needed technological and administrative improvements," the release said.

The test was the first such national test of cellphone alerts. The alerts can be used to inform cell phone users about the weather, missing children and other emergency situations. It also allows the president, whoever that may be at the time, to address the entire nation in a national emergency.

Unlike Amber alerts and some other types of alert messages, FEMA says the WEA alerts cannot be turned off.

The plan called for cell towers to broadcast the WEA test for about 30 minutes. Any cell phone turned on and within range of a tower, and when the wireless provider participated, got the message once. It read:

"THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed."

FEMA originally planned to conduct the WEA test in mid-September, but it was delayed because of Hurricane Florence.